In xerographic and solid ink printing applications, it is desirable to use release agent oils which are cost effective, clear, colorless, odorless or nearly so at room temperature and at operating temperatures, free of additives (such as acids, bases, peroxides, heavy metals, and the like) that can interfere with the fusing/transfer and sheet release performance of the fusing/transfer system and associated hardware, and free of or capable of producing minimal volatile emission compounds over the service life of the release agent oil.
In a typical solid ink print process, a thin film of oil is applied to the surface of a rotating metal drum, and the print heads jet the ink onto the oiled surface of the drum. Once the image is built on the drum, it is transferred to a media, such as a paper or a substrate. The oil acts as a release layer and reduces the adhesive force of the ink to the drum surface, which aids in the transfer efficiency of the ink from the drum surface to the media. In order to achieve high transfer efficiency and excellent print quality, the adhesive force between the media and the ink should be higher than the adhesive force between the ink and the oiled drum surface. Without the oil, the drum-ink adhesion is too high, resulting in poor transfer efficiency and poor image quality.
Various conventional oil compositions for a printing system have been proposed, the compositions having a wide range of additives and constituent materials. U.S. Pat. No. 6,183,929 to Chow et al. discloses a fuser member comprising a substrate, a layer thereover comprising a polymer and, on the polymeric layer, a coating of a release agent comprising a mixture of (a) an organosilane polymer concentrate containing amino-substituted or mercapto-substituted organosiloxane polymers, the concentrate having a viscosity of from about 50 to about 500 cSt, and (b) a nonfunctional organosiloxane polymer diluent having a viscosity of from about 100 to about 2,000 cSt. U.S. Pat. No. 7,208,259 to Badesha et al. discloses a fuser member comprising a substrate, a layer thereover comprising a polymer, and, on the polymeric layer, a coating of a release agent comprising a mixture of (a) an organosiloxane polymer concentrate containing amino-substituted organosiloxane and (b) a nonfunctional organosiloxane polymer diluent. U.S. Pat. No. 4,029,827 to Imperial et al. discloses polyorganosiloxanes having functional mercapto groups, which are applied to a heated fuser member in an electrostatic reproducing apparatus to form thereon a thermally stable, renewable, self-cleaning layer having superior toner release properties for electroscopic thermoplastic resin toners. The disclosures of U.S. Pat. Nos. 6,183,929, 7,208,259, and 4,029,827 are totally incorporated herein by reference in their entireties.
U.S. Pat. No. 4,101,686 to Strella et al. and U.S. Pat. No. 4,185,140 to Strella et al. disclose polymeric release agents having functional groups such as carboxy, hydroxyl, epoxy, amino, isocyanate, thioether, or mercapto groups. U.S. Pat. No. 5,157,445 to Shoji et al. discloses toner release oil having a functional organopolysiloxane of a certain formula. U.S. Pat. No. 4,251,777 to Martin discloses compositions containing organopolysiloxanes and thiofunctional polysiloxanes having at least one mercapto group which are effective as corrosion inhibitors and as release agents for metal substrates. U.S. Pat. No. 5,512,409 to Henry et al. teaches a method of fusing thermoplastic resin toner images to a substrate using amino functional silicone oil over a hydrofluoroelastomer fuser member. U.S. Pat. No. 5,516,361 to Chow et al. teaches a fusing member having a thermally stable FKM hydrofluoroelastomer surface and having a polyorgano T-type amino functional oil release agent. The disclosures of U.S. Pat. Nos. 4,101,686, 4,185,140, 5,157,445, 4,251,777, 5,512,409, 5,516,361, and 4,101,686 are totally incorporated herein by reference in their entireties.
These conventional release layer oils, such as typical silicone oils, emit volatile organic compounds (VOCs) when heated by the drum surface. For example, thermal degradation of release agents may result in the generation of volatile byproducts including, for example, formaldehyde (CH2O), formic acid (HCO2H), carbon dioxide (CO2), carbon monoxide (CO), hydrogen (H2), methanol (CH3OH), ammonia (NH3), hydrogen sulfide (H2S), trifluoropropionaldehyde (CF3CH2CHO), and the like. The abatement system of the solid ink printer pulls air, dust, particles, and volatile chemicals out of the printer cavity and into the environment with a fan, thereby releasing the VOCs into the environment. Many VOCs are hazardous to human health and harmful to the environment. In order to meet increasingly stringent environmental certifications (such as Blue Angel certification) and governmental regulations (such as EPEAT and EcoLogo), the VOCs emitted by the oil and exhausted into the environment should be reduced significantly.
As a result, there exists a need to develop an oil composition that exhibits low VOC emissions that can be produced without chemically altering or degrading the oil, while minimizing the change in viscosity of the oil.